Near-field light generating element, method of manufacturing near-field light generating element, near-field light head, method of manufacturing near-field light head, and information recording and playback device

ABSTRACT

A near-field light generating element has a core that propagates light flux from a light incident side to a light emission side while focusing the propagating light flux. A near-field light generating portion in the form of a metal film generates near-field light from the light flux. The core includes a first core, and a second core covering a side surface of the first core, and the core is formed in a polygonal shape when viewed from a Z direction. The metal film is placed on a side surface in the core, and is formed so that a width of an interface between the metal film and the core is narrower than a width of the side surface of the core.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a near-field light generating element that records and plays a variety of information on a magnetic recording medium using a near-field light with focused light flux, a method of manufacturing a near-field light generating element, a near-field light head, a method of manufacturing a near-field, light head, and an information recording and playback device.

2. Background Art

In recent years, along with an increase in the capacity of a hard disk or the like in computer equipment, the recording density of information in a single recording surface has increased. For example, in order to increase the recording capacity of a magnetic disk per unit area, there is a need to increase the surface recording density. Incidentally, as the recording density increases, the recording area occupied per bit on the recording medium is reduced. When the bit size is reduced, energy held by one bit of information comes close to the heat energy of room temperature, whereby there is a problem of thermal demagnetization in which the recorded information is reversed or disappears owing to thermal fluctuations or the like.

Although the in-plane recording method generally used is a method of recording the magnetism so that a direction of magnetization faces the in-plane direction of the recording medium, in this method, the recording information is easily lost due to the thermal demagnetization mentioned above. Thus, in order to solve the disadvantage, in recent years, a perpendicular recording method is adopted in which a magnetization signal is recorded in a direction perpendicular to the recording medium. This method is to record the magnetic information using the principle of causing a single magnetic pole to approach the recording medium. According to this method, the recording magnetic field faces a direction that is substantially perpendicular to a recording film. Since N-pole and S-pole are difficult to make form a loop within the recording film surface, information recorded in the vertical magnetic field easily maintains energetic stability. For that reason, the perpendicular recording method becomes resistant to the thermal demagnetization compared to the in-plane recording method.

However, recent recording media require further increasing high densities in response to the needs for performing the recording and playback of larger amounts and higher densities of information, or the like. For that reason, in order to suppress the influence between the adjacent magnetic domains or the thermal fluctuations to the minimum, one having strong coercive force is begun to be adopted as the recording medium. For that reason, even in the perpendicular recording method mentioned above, it is difficult to record information on the recording medium.

Thus, in order to solve the disadvantage mentioned above, a hybrid magnetic recording-type recording and playback head is provided in which the magnetic domain is locally heated using a spot light with the focused light or the near-field light to temporarily lower the coercive force, thereby performing the writing onto the recording medium in the meanwhile.

Among such recording and playback heads, a recording and playback head (hereinafter, referred to as near-field light head) using the near-field light mainly includes a slider, a recording element having a main magnetic pole and an return pole that are placed on the slider, a near-field light generating element that generates the near-field light from the irradiate laser light, a laser light source that irradiates laser light toward the near-field light generating element, and an optical waveguide that guides laser light generated from the laser light source to the near-field light generating element (for example, JP-A-2008-152897). The near-field light generating element has a core that propagates laser light while reflecting the same, a light flux propagation element having a cladding that comes into close contact with the core and seals the core, and a metal film that is placed between the core and the cladding to generate the near-field light from the laser light. The core is drawn so that the cross-sectional area perpendicular to the propagation direction of laser light facing from one end side (light incident side) to the other end side (light emission side) is gradually reduced, and is configured so as to propagate the laser light toward the other end side while focusing the same. Moreover, the metal film mentioned above is placed on a side surface of the other end side in the core.

In the case of using the near-field light head configured in this manner, a variety of information is recorded on the recording medium by generating the near-field light and applying the recording magnetic field. That is, laser light emitted from the laser light source is incident to the light flux propagation element via the optical waveguide. Moreover, laser light incident to the light flux propagation element is propagated through the cores and reaches the metal film. Then, since free electron within the metal film is uniformly vibrated by laser light, plasmon is excited and generates the near-field light on the other end side of the core in the state of being localized. As a result, the magnetic recording layer of the magnetic recording medium is locally heated by the near-field light and coercive force is temporarily lowered.

Furthermore, by providing the driving electric current to the recording element simultaneously with the irradiation of the laser light mentioned above, the recording magnetic field is locally applied to the magnetic recording layer of the magnetic recording medium adjacent to the tip of the main magnetic pole. As a result, it is possible to record a variety of information on the magnetic recording layer in which the coercive force is temporarily lowered. That is, by the cooperation of the near-field light with magnetic field, the recording to the magnetic recording medium can be performed.

However, in order to promote new high density of the recording medium, there is a need to reduce a spot size of the near-field light and more locally heat the magnetic recording layer of the magnetic recording medium, thereby suppressing the influence of the thermal fluctuation phenomenon mentioned above or the like. In order to reduce the spot size of the near-field light, a reduction in the width (width of the interface between the metal film and the core when viewed from the propagation direction of laser light) of the metal film is considered.

In this case, in the related art, since the core is formed according to the width of the metal film, the width (a width of an interface between the core and the metal film when viewed from the propagation direction of laser light) of the core is reduced along with the reduction in metal film.

However, when reducing the width of the core, the loss of the laser light propagated through the core is increased, whereby there is a problem in that a sufficient amount of light cannot be obtained. That is, the spot size of the near-field light can be reduced, but the amount of light is lowered.

SUMMARY OF THE INVENTION

Thus, the present invention was made in view of such situation, and an object thereof is to provide a near-field light generating element which can ensure an amount of light and then can reduce the spot size of the near-field light, a method of manufacturing the near-field light generating element, a near-field light head, a method of manufacturing the near-field light head, and an information recording and playback device.

The present invention provides means as below so as to solve the problems mentioned above.

According to the present invention, there is provided a near-field light generating element which propagates the light flux introduced to one end side while focusing the light flux toward the other end side and emits the light flux to the outside after creating the near-field light, the element having a core that propagates the light flux toward the other end side, and a near-field light generating portion which is placed along the propagation direction of the light flux facing from the one end side toward the other end side in the core to propagate the light flux along the interface between the near-field light generating element and the core, and generates the near-field light from the light flux, the core includes a first core, and a second core that covers the first core from the opposite side of the near-field light generating portion with the first core interposed therebetween, and an external end portion of the second core is situated further to the outside than an external end portion of the near-field light generating portion when viewed from the propagation direction.

According to this configuration, since the external end portion in the second core is situated further to the outside than the external end portion of the near-field light generating portion, the width of the near-field light generating portion is formed to be narrower than the width between core and the near-field light generating portion in the entire core when viewed from the propagation direction. For that reason, it is possible to generate the near-field light having the spot size smaller than the width of the interface between the cores and the near-field light generating portion in the entire core, and suppress a decline in propagation efficiency of light flux along with a reduction in spot size. As a result, it is possible to reduce the spot size of the near-field light after ensuring the amount of light.

Furthermore, the first core and the second core are formed of the same material.

According to this configuration, it is possible to prevent the reflection or the absorption of the light flux in the interface between the first core and the second core, thereby effectively diffusing the light flux from one end side of the cores toward the other end side thereof.

Furthermore, the near-field light generating element further has a cladding that covers the core in the state of exposing the other end surface of the core to the outside, and the first core, the second core, and the cladding are configured so that the refractive index is increased in the order of the cladding, the second core, and the first core.

According to the configuration, since the light flux totally reflected on the interface between the second cores and the cladding can be gradually focused toward the center (the first core), the propagation efficiency of the light flux can be improved.

Furthermore, the other end surface of the core is formed in a triangular shape or a trapezoidal shape when viewed from the propagation direction.

According to this configuration, it is possible to effectively reflect the light flux propagated through the core toward the near-field light generating portion.

Furthermore, a light shielding film is formed so as to cover the second core from the opposite side of the first core with the second core interposed therebetween.

In this configuration, by forming the light shielding film so as to cover the second core, the light flux incident to the core is propagated toward the other end side while being reflected from the interface between the light shielding film and the second core without leaking to the outside. As a result, it is possible to effectively make the light flux incident to the near-field light generating portion, which can improve the generation efficiency of the near-field light.

Furthermore, the first core has a plurality of side surfaces that is extended along the propagation direction, the plurality of side surfaces has a first side surface on which the near-field light generating element is placed, and a second side surface placed along a direction intersecting the plane direction of the first side surface on both sides of the first side surface when viewed from the propagation direction, and the external end portion of the near-field light generating portion is placed on the same surface as the second side surface of the first core when viewed from the propagation direction.

According to this configuration, since the first core and the near-field light generating portion are placed so as to overlap with each other when viewed in a direction perpendicular to the propagation direction, it is possible to make the light flux propagated up to the other end side of the core incident to the near-field light generating portion without leaking. Thus, the generation efficiency of the near-field light can be improved.

Furthermore, according to the present invention, there is provided a method of manufacturing the near-field light generating element which propagates the light flux introduced to one end side while focusing the light flux toward the other end side and emits the light flux to the outside after creating the near-field light, the element having a core that propagates the light flux toward the other end side, and a near-field light generating portion which is placed along a propagation direction of the light flux facing from the one end side toward the other end side in the core to propagate the light flux along an interface between the near-field light generating element and the core, and generates the near-field light from the light flux, the method including a near-field light generating portion forming process of forming a base material of the near-field light generating portion; a first core forming process of forming a base material of a first core among the cores so as to cover the near-field light generating portion; a patterning process of collectively patterning the base material of the first core, and the base material of the near-field light generating portion; and a second core forming process of forming a second core of the core so as to cover the first core from the opposite side of the near-field light generating portion with the first core interposed therebetween.

According to this configuration, by collectively patterning the base material of the first core and the base material of the near-field light generating portion by the same patterning process, the width of the interface between the near-field light generating portion and the first core can be equally formed. Moreover, by forming the second core so as to cover the first core after the patterning process, it is possible to simply form the near-field light generating portion having the width narrower than the width of the interface between the near-field light generating portion when viewed from the propagation direction and the core in the entire core. In addition, for example, unlike a case where the first core and the near-field light generating portion are patterned by separate processes, respectively, the near-field light generating portion and the first core can be accurately positioned.

Furthermore, according to the present invention, there is provided a method of manufacturing a near-field light head which heats a magnetic recording medium rotating in a given direction using the method of manufacturing the near-field light generating element of the present invention and causes a magnetization reversal by applying recording magnetic field to the magnetic recording medium to record information, the method include a magnetic pole forming process of forming a base material of the magnetic pole generating the recording magnetic field before the near-field light generating portion forming process, and in the patterning process, the base material of the magnetic pole is collectively patterned by the same process together with the base material of the first core and the base material of the near-field light generating portion.

According to this configuration, by collectively patterning the base material of the magnetic pole by the same patterning process together with the first cores and the base material of the near-field light generating portion, the first core and the external end portion of the near-field light generating portion and the magnetic pole are placed on the same surface when viewed from the propagation direction. As a result, for example, unlike a case where the first core, the near-field light generating portion, and the magnetic pole are patterned by separate processes, respectively, it is possible to accurately position the near-field light generating portion, the core, and the magnetic pole. In addition, since the cores, the near-field light generating portion, and the magnetic pole can be positioned without using an expensive positioning device, the cost of the device can be reduced.

In this case, the magnetic pole is formed so as to cover the near-field light generating portion from the opposite side of the first core with the near-field light generating element interposed therebetween. For that reason, it is possible to accurately position the generation position of the near-field light and the generation position of the magnetic field from the magnetic pole, whereby the reliability of the writing of the near-field light head itself can be raised to promote increased quality.

Furthermore, even in a case where Plasmon resonance is not generated in the near-field light generating portion but the light flux transmits through the near-field light generating portion, the light flux can be incident to the near-field light generating portion again by reflecting the light flux to the magnetic pole to return into the core. As a result, the generation efficiency of the near-field light generating portion can be further improved. In addition, since it is possible to suppress that the light flux leaks to the outside without generating the Plasmon resonance in the near-field light generating portion, the spot of the extremely small near-field light can be created only in the vicinity of the core.

Furthermore, according to the present invention, there is provided a near-field light head which heats a magnetic recording medium rotating in a given direction and causes the magnetization reversal by applying the recording magnetic field to the magnetic recording medium to record information, the near-field light head includes a slider that is placed opposite on a surface of the magnetic recording medium; a recording element that is placed on a tip side of the slider and has a magnetic pole generating the recording magnetic field; the near-field light generating element according to a first aspect that is fixed adjacent to the recording element in the state where the other end side faces the magnetic recording medium side; and light flux introduction means that is fixed to the slider and introduces the light flux from the one end side into the core.

According to this configuration, since the near-field light generating element of the present invention is included, it is possible to suppress the influence of the thermal fluctuation phenomenon or the like to perform stable recording. Thus, the reliability of the near-field light head itself can be raised, which can promote increased quality.

Furthermore, the first core has a plurality of side surfaces that is extended along the propagation direction, the plurality of side surfaces has a first side surface on which the near-field light generating element is placed, and a second side surface that is placed along a direction intersecting the plane direction of the first side surface on both sides of the first side surface when viewed from the propagation direction, the magnetic pole is placed opposite to the first side surface of the first core with the near-field light generating portion therebetween, and an external end portion of the magnetic pole is placed on the same surface as the second side surface of the first core when viewed from the propagation direction.

According to this configuration, since the magnetic pole is formed so as to cover the near-field light generating portion from the opposite side of the core with the near-field light generating element interposed therebetween, the generation position of the near-field light and the generation position of the magnetic field can be accurately positioned, which can raise the reliability of the writing of the near-field light head itself to promote increased quality.

Furthermore, even in a case where Plasmon resonance is not generated in the near-field light generating portion but the light flux transmits through the near-field light generating portion, the light flux can be incident to the near-field light generating portion again by reflecting the light flux to the magnetic pole to return into the core. As a result, the generation efficiency of the near-field light generating portion can be further improved. In addition, since it is possible to suppress that the light flux leaks to the outside without generating the Plasmon resonance in the near-field light generating portion, the spot of the extremely small near-field light can be created in the vicinity of the core only.

Furthermore, between the near-field light generating portion and the magnetic pole, a separation film is formed which forms an image between the near-field light generating portion and the magnetic field.

According to this configuration, when the near-field light generating portion and the magnetic pole are formed of a metallic material having conductivity, the near-field light generating portion and the magnetic pole can be electrically insulated, and the alloying of the near-field light generating portion can be suppressed. Thus, the movement of free electrons in the near-field light generating portion is not adversely affected. For that reason, the generation efficiency of the near-field light can be further improved.

Furthermore, according to the present invention, there is provided an information recording and playback device which includes the near-field light head of the present invention; a beam that is movable in a direction parallel to the surface of the magnetic recording medium and supports the near-field light head on a tip side in the state of being rotatable around two axes which are parallel to the surface of the magnetic recording medium and are perpendicular to each other; a light source that makes the light flux incident to the light flux introduction means; an actuator that supports a proximal end side of the beam and moves the beam toward a direction parallel to the surface of the magnetic recording medium; a rotation driving portion that rotates the magnetic recording medium in the given direction; and a control portion that controls the operation of the recording element and the light source.

According to this configuration, since the near-field light head of the present invention is included, the reliability of the writing can be raised, which can promote increased quality.

According to the near-field light generating element according to the present invention and the method of manufacturing the same, the spot size of the near-field light can be reduced after ensuring the quantity of light.

According to the near-field light head and the information recording and playback device according to the present invention, it is possible to suppress the influence of the thermal fluctuation phenomenon or the like mentioned above to perform stable recording. Thus, the reliability of the writing is high and it is possible to support the high quality recording, whereby the high quality can be promoted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of an information recording and playback device in an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a recording and playback head.

FIG. 3 is an enlarged cross-sectional view of a side surface of an outflow end side of the recording and playback head.

FIG. 4 is a diagram taken from an arrow A of FIG. 3.

FIG. 5 is a diagram taken from an arrow B of FIG. 3.

FIG. 6 is an enlarged view of a portion C of FIG. 3.

FIG. 7 is an enlarged view of the vicinity of a laser light source.

FIG. 8 is an explanatory diagram upon recording and playing information by the information recording and playback device and an enlarged cross-sectional view corresponding to FIG. 3.

FIG. 9 is an explanatory diagram upon recording and playing information by the information recording and playback device and an enlarged cross-sectional view corresponding to FIG. 5.

FIGS. 10A to 10D are diagrams corresponding to FIG. 5 and process diagrams for describing a manufacturing method of a near-field light generating element.

FIGS. 11A to 11E are diagrams corresponding to FIG. 5 and process diagrams for describing a manufacturing method of a near-field light generating element.

FIG. 12 is an enlarged cross-sectional view of a side surface of an outflow end side of a recording and playback head in a second embodiment.

FIG. 13 is an enlarged view of a portion D of FIGS. 11A to 11E.

FIGS. 14A to 14C are cross-sectional views of the outlet end side of the recording and playback head, FIG. 14A is a cross-sectional view taken along lines E-E of FIG. 12, FIG. 14B is a cross-sectional view taken along lines F-F, and FIG. 14C is a cross-sectional view taken along lines G-G lines.

FIG. 15 is a cross-sectional view corresponding to FIG. 13 that shows another configuration of a light flux propagation element.

FIG. 16 is a diagram corresponding to FIG. 3 that shows another configuration of the recording and playback head.

FIG. 17 is an enlarged view of an outflow end side of a recording and playback head in a third embodiment.

FIG. 18 is a diagram taken in the direction of an arrow H of FIG. 16.

FIG. 19 is a diagram that shows another configuration of a third embodiment.

FIG. 20 is a diagram corresponding to FIG. 5 that shows a recording and playback head in a fourth embodiment.

FIGS. 21A and 21B are process diagrams for describing a manufacturing method of the recording and playback head corresponding to FIG. 10.

FIG. 22 is a diagram that shows a recording and playback head in a fifth embodiment corresponding to FIG. 5.

FIGS. 23A to 23C are process diagrams for describing a manufacturing method of the recording and playback head corresponding to FIG. 12.

FIG. 24 is a diagram that shows another configuration of the recording and playback head corresponding to FIG. 5.

FIG. 25 is a diagram that shows a recording and playback head in a sixth embodiment corresponding to FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

Next, exemplary embodiments of the present invention will be described with reference to the drawings.

In addition, an information recording and playback device 1 of the present embodiment is a device that performs the recording and playback on a disk D using a hybrid magnetic recording method in which a near-field light R cooperates with recording magnetic field with a disk D (a magnetic recording medium) having a perpendicular recording layer d2 (see FIG. 2).

(First Embodiment)

(Information Recording and Playback Device)

FIG. 1 is a configuration diagram of an information recording and playback device.

As shown in FIG. 1, the information recording and playback device 1 of the present embodiment includes a recording and playback head (a near-field light head) 2, abeam 3 that supports the recording and playback head 2, a light flux incident mechanism 4 that makes laser light (light flux) L (see FIG. 2) incident to the recording and playback head 2, an actuator 5 that moves the beam 3, a spindle motor (a rotation driving portion) 6 that rotates the disk D in a given direction, a control portion 8 that collectively controls the respective components mentioned above, and a housing 9 that accommodates the respective components in an inner portion.

The housing 9 is formed of a metal material such as aluminum in a rectangular shape when seen from above, and the inside thereof is formed with a concave portion 9 a that accommodates the respective components. Furthermore, a lid (not shown) is fixed to the housing 9 in an attachable and detachable manner so as to close the opening of the concave portion 9 a. A spindle motor 6 is attached to an approximately center of the concave portion 9 a, whereby the disk D is fixed in a freely attachable and detachable manner by engaging with the center hole in the spindle motor 6. In addition, in the present embodiment, a case is described as an example where three discs D are fixed to the spindle motor 6. However, the number of the disk D is not limited to three.

The actuator 5 is attached to the corner portion of the concave portion 9 a. A carriage 11 is attached to the actuator 5 via a bearing 10. The carriage 11 is formed of a metal material, for example, through cutting, and has a three-layer structure so that a portion facing from a proximal end portion 11 a to a tip to be fixed to the actuator 5 via the bearing 10 is placed on an upper surface of the disk D. That is, when being viewed from the side surface, the carriage 11 is formed so as to become an E shape. Moreover, the proximal end side of the beam 3 is fixed to each tip of the carriage 11 divided into three layers. Thus, the actuator 5 supports the proximal end side of the beam 3 via the carriage 11, whereby the beam 3 can be scanned and moved toward an XY direction parallel to a disc surface (a surface of the magnetic recording medium) D1 (see FIG. 2).

As mentioned above, the beam 3 can be moved in the XY direction together with the carriage 11 by the actuator 5 and supports the recording and playback head 2 on the tip side thereof in the state of being rotatable around two axes (X axis and Y axis) that are parallel to the disc surface D1 and are perpendicular to each other. In addition, the beam 3 and the carriage 11 are adapted to be retreated from the upper portion of the disk D by the driving of the actuator 5 when the rotation of the disk D is stopped.

(Recording and Playback Head)

FIG. 2 is an enlarged cross-sectional view of the recording and playback head, and FIG. 3 is an enlarged cross-sectional view of a side surface of an outflow end side of the recording and playback head.

As shown in FIGS. 2 and 3, the recording and playback head 2 is a head that records and plays a variety of information on the rotating disk D using the near-field light R created from the laser light L. The recording and playback head 2 includes a slide 20 that is placed opposite to the disk D in the state of floating from the disk surface D1 by a predetermined distance H, a recording element 21 that records information on the disk D, a playback element 22 that plays information recorded on the disk D, and a near-field light generating element 26 that propagates the introduced laser light L while focusing the same and emits the laser light after creating the near-field light R.

The slider 20 is formed of a light transmitting material such as quartz glass, ceramic such as AlTiC (altic) or the like in a rectangular shape. The slider 20 has an opposite surface 20 a facing the disk D, and is supported so as to hung on the tip of the beam 3 via a gimbal portion 30 (see FIG. 2). The gimbal portion 30 is a component in which the movement is restricted so as to be displaced only around the X axis and the Y axis. As a result, the slider 20 is freely rotated around two axes (the X axis and the Y axis) that are parallel to the disc surface D1 and perpendicular to each other as mentioned above.

Furthermore, on the opposite surface 20 a, a convex portion 20 b is formed which generates pressure for floating from viscosity of an air flow generated by the rotating disk D. The convex portion 20 b is formed so as to be extended along a longitudinal direction (the X direction), and two convex portions 20 b are formed in a left and right (the Y direction) direction so as to be arranged in a rail shape at intervals. However, the convex portion 20 b is not limited to this case, but may be any irregularity if one is designed so that a positive pressure trying to separate the slider 20 from the disc surface D1 and a negative pressure trying to attract the slider 20 to the disc surface D1 are adjusted and the slider 20 is caused to float in an optimal state. In addition, the surface of the convex portion 20 b is called an ABS (Air Bearing Surface) 20 c.

Moreover, the slider 20 is subjected to a floating force from the disc surface D1 by two convex portions 20 b. Meanwhile, the beam 3 is bent in the Z direction perpendicular to the disc surface D1 to absorb the floating force of the slider 20. That is, the slider 20 is subjected to force by which the same is pressed to the disc surface D1 side by the beam 3 when floating. Thus, the slider 20 floats in the state of being separated from the disc surface D1 by a predetermined distance H as mentioned above by balance of both forces. In addition, since the slider 20 is adapted to rotate around the X axis and the Y axis by the gimbal portion 30, the slider 20 floats in the state in which the posture is always stable.

In addition, the air flow generated by the rotation of the disk D flows in from the inflow end side (the X direction proximal end side of the beam 3) of the slider 20, and then flows along the ABS 20 c and is discharged from the outflow end side (the X direction tip side of the beam 3) of the slider 20.

As shown in FIG. 3, the recording element 21 is an element that causes a recording magnetic field to act on the disk D to record information, and includes a return pole 31 that is fixed to the side surface (a tip surface) of the outflow end side of the slider 20, a main magnetic pole 33 that is connected to the return pole 31 via a magnetic circuit 32 and generates the recording magnetic field perpendicular to the disk D between the disk D and the return pole 31, and a coil 34 that is wound around the magnetic circuit 32 about the magnetic circuit 32 in a spiral shape. That is, the return pole 31, the magnetic circuit 32, the coil 34, and the main magnetic pole 33 are placed in an aligned state in order from the outflow end side of the slider 20.

Both magnetic poles 31 and 33 and the magnetic circuit 32 are formed of a high saturation magnetic flux density (Bs) material (for example, CoNiFe alloy, CoFe alloy or the like) having a high magnetic flux density. Furthermore, the coil 34 is placed between the adjacent coil lines, between the magnetic circuits 32, and between both magnetic poles 31 and 33 at a gap, and is molded by an insulator 35 in this state. Moreover, the coil 34 is adapted so that electric current modulated depending on information is supplied from the control portion 8. That is, the magnetic circuit 32 and the coil 34 generally constitute an electromagnet. In addition, the main magnetic pole 33 and the return pole 31 are designed so that the end surface (the end surface of the Z direction) facing the disk D so as to be flush with the ABS 20 c of the slider 20. Furthermore, the tip portion 33 a (the emission side of the laser light L) of the main magnetic pole 33 is protruded from the insulator 35 toward the playback element 22 side and is buried within a first cladding 24 a described later. In addition, the tip portion 33 a of the main magnetic pole 33 may be formed of a material (a material having a high saturation magnetic flux density) different from the proximal end portion.

FIG. 4 is a diagram taken in the direction of an arrow A of FIG. 3, and FIG. 5 is a diagram taken in the direction of an arrow of B of FIG. 3.

As shown in FIGS. 3 to 5, a light flux propagation element 25 is fixed adjacent to the X direction side of the main magnetic pole 33 of the recording element 21 in the state in which the incident side (the Z direction one end side) of laser light L faces upward the slider 20 and the emission side (the Z direction other end side) faces the disk D side. The light flux propagation element 25 includes a core or core portion 23 that propagates laser light L introduced from one end side to the other end side facing the disk D, and a cladding 24 that comes into close contact with the core 23, and the light flux propagation element 25 is formed in an approximately plate shape as a whole.

The core 23 is gradually drawn from one end side to the other end side and can propagate laser light L while gradually focusing the same in the inner portion. Specifically, the core 23 has a reflection surface 23 a, a light flux focusing portion 23 b, and a near-field light creating portion 23 c from one end side, and is formed in a triangular shape when viewed from the propagation direction (the Z direction) of laser light L.

The reflection surface 23 a reflects the laser light L introduced from a light waveguide 42 described later in a direction different from the introduction direction. In the present embodiment, the reflection surface 23 a reflects laser light L so that the direction thereof is changed by about 90°. Laser light L introduced from the optical waveguide 42 by the reflection surface 23 a is propagated toward the other end side while repeating the total reflection within the core 23.

The light flux focusing portion 23 b is a portion that is drawn so that a cross-sectional area (a cross-sectional area of the XY direction) perpendicular to the Z direction facing from one end side to the other end side is gradually reduced, and the light flux focusing portion 23 b propagates the introduced laser light L while focusing the same. That is, the light flux focusing portion 23 b can gradually narrow the spot size of laser light L introduced into the light flux focusing portion 23 b to a small size.

The near-field light creating portion 23 c is a portion that is further drawn from the end portion of the light flux focusing portion 23 b toward the other end side thereof. Specifically, the near-field light creating portion 23 c is drawn by a sloped surface 23 h that is formed so as to face the playback element 22 in the state of being tilted to the optical axis (the Z direction) of the laser light L propagated in the inner portion in the vicinity of the other end side of the core 23. The other end side of the core 23 is in a pointed state by the sloped surface 23 h.

In addition, in the present embodiment, the light flux focusing portion 23 b and the near-field light creating portion 23 c are formed so as to have three side surfaces along the Z direction, and one side surface 23 g of them is placed opposite to the main magnetic pole 33. In this case, on both ends (both ends of the Y direction) of the side surface 23 g, a pair of side surfaces 23 d is formed which is extended toward the playback element 22 along a direction intersecting the Y direction (the plane direction) of the side surface 23 g. As a result, the core 23 is formed in a triangular shape that is tapered toward the X direction when viewed from the Z direction. For that reason, as shown in FIG. 5, an end surface 23 e exposed to the outside on the other end side of the near-field light creating portion 23 c is formed in a triangular shape. Furthermore, the end surface 23 e is designed so as to be flush with the ABS 20 c of the slider 20.

FIG. 6 is an enlarged view of a portion C of FIG. 3.

Herein, as shown in FIGS. 5 and 6, the other end side of the core 23 of the present embodiment is constituted by two-layer structures. Specifically, the other end side of the core 23 includes a first core 54 having a triangular shape when viewed from the Z direction, and a second core 55 formed so as to cover the first core 54. In this case, the first core 54 is formed over the all regions of the side surface (the side surface of the outflow end side) of the slider 20 in the Z direction, and constitutes the entire core 23 (from the reflection surface 23 a mentioned above to the near-field light creating portion 23 c). Meanwhile, the second core 55 is formed so as to cover the other end side of the first core in the Z direction and constitutes the near-field light creating portion 23 c from the other end side of the light flux focusing portion 23 b formed so as to cover the other end side of the first core 54. In addition, the forming region of the second core 55 may be formed so as to cover the whole first core 54 without being limited to the scope mentioned above. Furthermore, in FIG. 5, in both end portions of the second core 55 in the Y direction, a bottom portion 55 a is formed which is extended on the first cladding 24 a along the Y direction. However, if at least the first core 23 is covered, the bottom portion 55 a may be removed. In addition, in the description as below, the side surfaces of the first core 54 and the second core 55 will be described by the use of the same reference numerals of those of the side surfaces 23 d and 23 g of the core 23.

As shown in FIGS. 3 to 5, the cladding 24 is formed of a material having a refractive index lower than that of the core 23. The cladding 24 comes into close contact with the side surfaces 23 d and 23 g of the core 23 in the state of exposing the end surfaces 23 e of one end side and the other end side of the core 23 to the outside, and seals the core 23 in the inner portion. Specifically, the cladding 24 includes a first cladding 24 a that is formed so as to cover the side surface 23 g side of the core 23 between the core 23 and the recording element 21 (the main magnetic pole 33), and a second cladding 24 b that is formed so as to cover the side surface 23 d side between the core 23 and the playback element 22. In this manner, since the first cladding 24 a and the second cladding 24 b come into close contact with the side surfaces 23 d and 23 g of the core 23, a gap is not generated between the core 23 and the cladding 24. In addition, the tip portion 33 a of the main magnetic pole 33 mentioned above is buried in a center portion of the slider 20 in the other end side of the first cladding 24 a in the width direction (the Y direction), and the tip portion 33 a is exposed from the first cladding 24 a to the core 23 side.

In addition, an example of the combination of the material to be used as the cladding 24 and the core 23 will be described. For example, a combination is considered in which the core 23 (the first core 54 and the second core 55) is formed of quartz (SiO₂) and the cladding 24 is formed of quartz doped with fluorine. This case is a desirable combination since, when the wavelength of laser light L is 400 nm, the refractive index of the core 23 becomes 1.47 and the refractive index of the cladding 24 becomes less than 1.47.

Furthermore, a combination is also considered in which the core 23 (the first core 54 and the second core 55) is formed of quartz doped with germanium and the cladding 24 is formed of quartz (SiO2). This case is also a desirable combination since, when the wavelength of laser light L is 400 nm, the refractive index of the core 23 becomes greater than 1.47 and the refractive index of the cladding 24 becomes 1.47.

Particularly, since the force confining laser light L within the core 23 is increased as the refractive difference between the core 23 and the cladding 24 is increased, it is more desirable that tantalum oxide (Ta₂O₅: refractive index of 2.16 when the wavelength is 550 nm) be used for the core 23 (the first core 54 and the second core 55) and quartz, alumina (Al₂O₃) or the like is used for the cladding 24 to increase the difference in the refractive indexes between them. Furthermore, in the case of using laser light L of an infrared region, it is also efficient to form the core 23 (the first core 54 and the second core 55) by silicon (Si: refractive ratio is about 4) that is a material transparent to infrared light. In addition, in the present embodiment, the first core 54 and the second core 55 are formed of the same material, but the first core 54 and the second core 55 may be formed of the materials different from each other without being limited thereto. As the combination of the material of this case, a combination is desirable in which the refractive index is gradually increased from the cladding 24 to the second core 55 and the first core 54 (the refractive index is increased in the order of the cladding 24, the second core 55, and the first core 54). According to this configuration, since laser light L totally reflected by the interface 24 between the second core 55 and the cladding 24 can be gradually focused toward the center (the first core 54), the propagation efficiency of the laser light L can be improved.

Herein, a metal film (a near-field light generating portion) 51 is formed between the core 23 (the first core 54) and the first cladding 24 a (the opposite side of the second core 55 with the first core 54 interposed therebetween). The metal film 51 generates the near-field light R from laser light L propagated through the core 23, localizes the near-field light R between the other end side of the light flux propagation element 25 and the disk D, and is formed of, for example, gold (Au), platinum (Pt) or the like. The metal thin film 51 is placed on the side surface 23 g of the near-field light generating portion 23 c in the core 23 (the first core 54), and comes into contact with the first cladding 24 a, and the tip portion 33 a of the main magnetic pole 33 exposed from the first cladding 24 a. Furthermore, in the Z direction, the metal film 51 is formed so that one end side thereof is situated in the boundary portion between the near-field light creating portion 23 c and the light flux focusing portion 23 b and the other end side thereof is flush with the end surface 23 e of the core 23.

Furthermore, the metal film 51 is formed in an isosceles trapezoidal shape tapered toward the playback element 22 when viewed from the Z direction. At this time, a width W1 of an upper bottom (an interface between with the core 23) 51 a of the metal film 51 in the Y direction is formed so as to be equal to, or coextensive with, a width W2 of the side surface (the first side surface) 23 g of the first core 54 in the Y direction. As a result, the width W1 of the metal film 51 is formed so as to be narrower than a width W3 (a width except for the bottom portion 55 a) of the side surface 23 g of the core 23 (the second core 55). That is, the external end portion of the second core 55 is situated outside the sloped surface (the external end surface) 51 b of the metal film 51 when viewed from the Z direction. In addition, the sloped surface 51 b of the metal film 51 is placed on the same surface as the side surface (the second surface) 23 d of the first core 54. That is, the laminated body of the first core 54 and the metal film 51 is formed in a form similar to the core 23 when viewed from the Z direction (see FIG. 5).

Furthermore, a light shielding film 52 is formed between the core 23 (the second core 55) and the second cladding 24 b. The light shielding film 52 is formed of a material having high reflectance such as aluminum (Al) and is formed so as to cover the side surface 23 d in the second core 55 of the near-field light creating portion 23 c. That is, the near-field light creating portion 23 c is configured so that the side surface 23 g is covered with the metal film 51 and the side surface 23 d is covered with the light shielding film 52. The light shielding film 52 is formed over a wide range further than the metal film 51 in the Z direction. Specifically, the light shielding film 52 is formed so that one end side thereof is situated on the other end side of the light flux focusing portion 23 b and the other end side thereof is flush with the end surface 23 e of the core 23. In addition, the light shielding film 52 may be formed in the range equal to or greater than the metal film 51 in the Z direction. Furthermore, both end portions of the light shielding film 52 in the Y direction may be formed so as to completely cover the bottom portion 55 a of the second core 55.

Incidentally, as shown in FIG. 3, an optical waveguide 42 is fixed to the upper surface (one end side of the Z direction) of the slider 20. The optical waveguide 42 is constituted by the core 42 a and the cladding 42 b formed so as to cover the core 42 a, and laser light L is propagated in the core 42 a. The tip of the optical waveguide 42 is connected to one end side of the core 23 of the light flux propagation element 25, and emits laser light L toward the reflection surface 23 a. In addition, the core 42 a and the cladding 42 b are formed of the same materials as those of the core 23 and the cladding 24 mentioned above.

Meanwhile, as shown in FIG. 1, the proximal end side of the optical waveguide 42 is drawn along the beam 3 and the carriage 11 and is connected to the laser light source 43. As shown in FIGS. 1 and 7, the laser light source 43 is implemented on a control substrate 44 attached to the side surface of the proximal end portion 11 a of the carriage 11 together with various electronic components such as an IC chip (not shown). Particularly, the laser light source 43 emits laser light L in the state of linear polarization. That is, the laser light source 43 and the optical waveguide 42 functions as the light flux incident mechanism 4 that makes laser light L incident to the recording and playback head 2 in the state of linear polarization. In addition, FIG. 7 is an enlarged view of the periphery of the laser light source.

The control substrate 44 with the laser light source 43 implemented thereon is connected to the control portion 8 by a flexible flat cable (a flexible substrate) 45. As a result, the control portion 8 sends electrical signal to each component to perform an overall control. Particularly, the laser light source 43 is configured so that the timing of emitting laser light L is controlled by the control portion 8.

The playback element 22 is a magneto-resistance effect film, in which the electrical resistance is converted depending on the magnitude of the magnetic field leaking from the perpendicular recording layer d2 (see FIG. 2) of the disk D, and is formed on the surface of the cladding 24 (the second cladding 24 b) of the side opposite to the recording element 21 with the light flux propagation element 25 therebetween. Bias current is supplied from the control portion 8 to the playback element 22 via a lead film (not shown) or the like. As a result, the control portion 8 can detect a change in magnetic field leaking from the disk D as a change in voltage, whereby the playback of the signal from the change in voltage can be performed.

In addition, as shown in FIG. 2, the disk D of the present embodiment uses a vertical two layer film disk D that is constituted by at least two lasers of a perpendicular recording layer d2 having an easy magnetization axis in a direction vertical to the disc surface D1 and a soft magnetic layer d3 formed of high permeability material. As such a disk D, for example, a disc is used in which the soft magnetic layer d3, an intermediate layer d4, the perpendicular recording layer d2, a protective layer d5, and a lubricant layer d6 are sequentially formed on the substrate d1.

As the substrate d1, for example, an aluminum substrate, a glass substrate or the like are adopted. The soft magnetic layer d3 is a high permeability layer. The intermediate layer d4 is a crystal control layer of the perpendicular recording layer d2. The perpendicular recording layer d2 is a perpendicular anisotropy magnetic layer and uses, for example, CoCrPt-based alloy. The protective layer d5 is to protect the perpendicular recording layer d2 and uses, for example, a DLC (diamond-like carbon) film. The lubricant film d6 uses, for example, a fluorine-based liquid lubricant agent.

(Information Recording and Playback Method)

Next, a case will be described below where a variety of information is recorded and played on the disk D by the information recording and playback device 1 configured in this manner.

Firstly, as shown in FIG. 1, the spindle motor 6 is driven to rotate the disk D in a given direction. Next, the actuator 5 is operated and the beam 3 is scanned in the XY direction via the carriage 11. As a result, it is possible to position the recording and playback head 2 in a desired position on the disk D. At this time, the recording and playback head 2 is subjected to a floating force by two convex portions 20 b formed on the opposite surface 20 a of the slider 20 and is pressed to the disk D side by the beam 3 or the like by predetermined force. The recording and playback head 2 floats to a position separated from the upper portion of the disk D by a predetermined distance H.

Furthermore, even when the recording and playback head 2 is subjected to wind pressure generated due to undulations of the disk D, since the displacement of the recording and playback head 2 in the Z direction is absorbed by the beam 3 and can be displaced around the XY direction axis by the gimbal portion 30, the wind pressure due to the undulations can be absorbed. For that reason, it is possible to cause the recording and playback head 2 to float in a stable state.

FIG. 8 is an explanatory diagram upon recording and playing information by the information recording and playback device and an enlarged cross-sectional view corresponding to FIG. 3, and FIG. 9 is a diagram corresponding to FIG. 5.

Herein, as shown in FIG. 8, in the case of performing the recording of information, the control portion 8 operates the laser light source 43 to emit the laser light L of the linear polarization, and supplies the coil 34 with the electric current modulated depending on information to operate the recording element 21.

Firstly, laser light L is incident from the laser light source 43 to the optical waveguide 42, and laser light L is guided to the slider 20 side. Laser light L emitted from the laser light source 43 progresses in the core 42 a of the optical waveguide 42 toward the tip (the outflow end) side, and is propagated into the core 23 of the light flux propagation element 25. Laser light L propagated into the core 23 is reflected by the reflection surface 23 a by about 90°, and then is propagated into the light flux focusing portion 23 b. Laser light L propagated into the light flux focusing portion 23 b is propagated toward the other end side situated on the disk D side while repeating the total reflection between core 23 and the cladding 24. Particularly, since the cladding 24 comes into close contact with the side surfaces 23 d and 23 g of the core 23, light does not leak to the outside of the core 23. Thus, it is possible to propagate the introduced laser light L to the other end side while constricting the same without waste and make the laser light L incident to the near-field light creating portion 23 c.

At this time, the core 23 is drawn so that the cross-sectional area perpendicular to the Z direction is gradually reduced. For that reason, laser light L is gradually squeezed as it is propagated into the light flux focusing portion 23 b, whereby the spot size is reduced.

As shown in FIGS. 8 and 9, next, laser light L having the reduced spot size is incident to the near-field light creating portion 23 c. The near-field light creating portion 23 c is further drawn toward the other end side, and the end surface 23 e has the size equal to or less than the wavelength of light. In this case, two side surfaces 23 d of the near-field light creating portion 23 c is shield by the light shielding film 52. Thus, laser light L incident to the near-field light creating portion 23 c is propagated while being reflected by the interface between the light shielding film 52 and the near-field light creating portion 23 c without leaking to the second cladding 24 b side. Moreover, when laser light L propagated to the near-field light creating portion 23 c is incident to the metal film 51, the surface Plasmon is excited to the metal film 51. Herein, the surface Plasmon is propagated toward the other end side of the core 23 along the interface of the metal film 51 and the core 23 (the near-field light creating portion 23 c) while being enhanced by the resonance effect. Moreover, at the time of reaching the other end side, the surface Plasmon becomes the near-field light R having strong light intensity and leaks to the outside. That is, it is possible to localize the near-field light R between the other end side of the light flux propagation element 25 and the disk D. Then, the disk D is locally heated by the near-field light R and coercive force is temporarily lowered.

Meanwhile, when the electric current is supplied to the coil 34 by the control portion 8, since the current magnetic field generates the magnetic field within the magnetic circuit 32 by the principle of electromagnet, it is possible to generate the recording magnetic field of the vertical direction with respect to the disk D between the main magnetic pole 33 and the return pole 31. Then, the magnetic flux generated from the main magnetic pole 33 directly escapes the perpendicular recording layer d2 of the disk D and reaches the soft magnetic layer d3. As a result, it is possible to perform the recording in a state in which the magnetization of the perpendicular recording layer d2 faces vertically to the disc surface D1. Furthermore, the magnetic flux reaching the soft magnetic layer d3 returns to the return pole 31 via the soft magnetic layer d3. At this time, the magnetic flux does not influence in the direction of the magnetization upon returning to the return pole 31. This is because the area of the return pole 31 facing the disc surface D1 is greater than that of the main magnetic pole 33, and thus, force is not generated in which the magnetic flux density greatly reverses the magnetization. That is, the recording can be performed only on the main magnetic pole 33 side.

As a result, it is possible to perform the recording of information by the hybrid magnetic recording method in which the near-field light R cooperates with the recording magnetic field generated in both magnetic poles 31 and 33. In addition, since the recording is performed by the perpendicular recording method, the recording is hardly affected by the thermal fluctuation phenomenon or the like and stable recording can be performed. Thus, the reliability of the writing can be enhanced.

Furthermore, in the case of playing information recorded on the disk D, when the coercive force of the disk D is temporarily lowered, the playback element 22 receives the magnetic field leaking from the perpendicular recording layer d2 of the disk D, and the electric resistance is changed depending on the magnitude thereof. Thus, the voltage of the playback element 22 is changed. As a result, the control portion 8 can detect a change in magnetic field leaking from the disk D as a change in voltage. Moreover, the control portion 8 can perform the playback of information recorded on the disk D by performing the playback of the signal from the change in voltage.

(Manufacturing Method of Recording and Playback Head)

Next, a manufacturing method of the recording and playback head 2 having the near-field light generating element 26 mentioned above will be described. FIGS. 10 and 11 are diagrams corresponding to FIG. 5 and process diagrams for describing the manufacturing method of the near-field light generating element. In addition, in the description mentioned below, among the manufacturing processes of the recording and playback head 2, a manufacturing process of the near-field light generating element will be mainly and specifically described.

In the present embodiment, a substrate 120 (for example, AlTiC (altic) or the like) is provided in which a plurality of slider 20 forming regions is aligned along the Y direction and the Z direction, the recording element 21, the near-field light generating element 26, and the playback element 22 are sequentially formed on each forming region of the slider 20 in the substrate 120 to form a plurality of recording and playback heads 2 aligned along the Y direction and the Z direction, and then the dicing is performed for each forming region of the recording and playback head 2, thereby manufacturing the recording and playback head 2.

Firstly, as shown in FIG. 10A, the recording element 21 is formed on the substrate 120 and is molded by insulator 35. After that, the base materials of the light flux propagation element 25 and the metal film 51 are formed on the insulator 35 (the first cladding forming process, the near-field light generating portion forming process, and the first core forming process). Specifically, the base materials (the first cladding base material 124 a, the metal film base material 151, and the first core base material 154) are formed on the substrate 120 (the insulator 35) in the order of the first cladding 24 a, the metal film 51 (for example, about 20 nm), and the first core 54 (about several μm). In addition, after forming the respective base materials 124 a, 151, and 154, the respective surfaces are polished by a CMP (Chemical Mechanical Polishing) or the like and become flat surfaces.

In addition, it is desirable that the metal film base material 151 be patterned in advance so that only a predetermined region remains after being formed on the whole surface on the first cladding base material 124 a. In the present embodiment, the metal film base material 151 is patterned so as to remain in a region equivalent to the near-field light creating portion 23 c (see FIG. 3) in the core base material 123 at least in the Z direction (so as to remove the metal film base material 151 of the region equivalent to the reflection surface 23 a and the light flux focusing portion 23 b (see FIG. 3)). In this case, in the region equivalent to the near-field light creating portion 23 c, the metal film base material 151 is interposed between the first core base material 154 and the first cladding base material 124 a, and in other regions, the first core base material 154 and the first cladding base material 124 a come into close contact with each other. As a result, since it is possible to improve the adherence between the first base material 154 and the first cladding base material 124 a, the film peeing during manufacturing can be suppressed.

Furthermore, in the near-field light generating element 26 (see FIGS. 2 and 3) mentioned above, when the metal film 51 is also formed in the light flux focusing portion 23 b of the core 23 in the Z direction, laser light L propagated through the light flux focusing portion 23 b is absorbed by the metal film 51 and becomes the loss, whereby the propagation efficiency of laser light L may decline. On the contrary to this, by forming the metal film 51 only in the region equivalent to the near-field light creating portion 23 c, it is possible to propagate laser light L between the core 23 and the cladding 24 by the total reflection condition up to the near-field light creating portion 23 c. For that reason, it is possible to guide more laser light L to the near-field light creating portion 23 c, which can improve the propagation efficiency of laser light L.

Next, as shown in FIG. 10B, on the first core base material 154, a mask pattern (not shown) is formed in which a region, where the first core base material 154 needs to be removed, is opened. Furthermore, a reactive ion etching (RIE) is performed via the mask pattern (a first patterning process). As a result, the first core base material 154 of the region with the opened mask pattern is etched, and the first core base material 154 of a rectangular shape when viewed in the Z direction. Furthermore, the first core base material 154 is formed in a trapezoidal shape that is tapered from one end side to the other end side when viewed from the X direction. Furthermore, the first core base material 154 is formed in a trapezoidal shape that is tapered from one end side to the other end side when viewed from the X direction. In addition, in the first patterning process, it is desirable that the first core base material 154 of the region with the opened mask pattern is not completely removed, but slightly remains (see the remaining portion 60 of FIG. 10B).

Next, as shown in FIG. 10C, in the plasma process of argon (Ar) or the like the first core base material 154 and the metal film base material 151 are subjected to a sputter etching (a second patterning process). In the second pattering process, when the first core base material 154 having the cross section of the rectangular shape is subjected to the sputter etching, corner portions of both sides of the first base material 154 in the Y direction are selectively etched, whereby a sloped surface 61 is formed. Moreover, when the etching is further continued in this state, the sloped surface 61 is etched while maintaining a certain angle with respect to the bottom surface (equivalent to the side surface 23 g of FIG. 5), whereby the first core base material 154 shown in FIG. 10D is formed.

After that, when the etching is continued, as shown in FIG. 11A, the width (width in the Y direction) and the height (height in the X direction) of the first core base material 154 are reduced while maintaining the similar shape, and the remaining portion 60 is removed. As a result, the first core 54 of a triangular cross section having three side surfaces is formed. In this manner, by performing the sputter etching on the first core base material 154 formed in the rectangular shape by the first patterning process, it is possible to form the first core 54 at any width or height when viewed from the Z direction.

Herein, when the etching is further continued after removing the remaining portion 60, the first core 54 is etched while maintaining the similar shape, and the metal film base material 151 is etched. In this case, as shown in FIG. 11B, the end portion (equivalent to the sloped surface 51 b in FIG. 5) of the metal film base material 151 in the Y direction is etched at the same angle as that between the side surface 23 d and the side surface 23 g of the core 23.

In this manner, the upper bottom 51 a has the same width as that of the side surface 23 g of the first core 54, and the metal film 51 is formed in which the sloped surface 51 b is placed on the same surface as the side surface 23 d of the first core 54. In addition, in order to completely remove the metal film base material 151 of the region other than the first core 54, the first cladding base material 124 a is also slightly etched. In this case, in the first patterning process mentioned above, by forming the remaining portion 60 in the first core base material 154, it is possible that the first cladding base material 124 a is over-etched in the second patterning process.

Next, as shown in FIG. 11C, the second core 55 is formed so as to cover the first core 54 and the metal film 51 (the second core forming process). Specifically, a second core base material (not shown) is formed so as to cover the whole first core 54, and then the second core base material is patterned so as to remain only in the other end side of the first core 54. In addition, the second core base material may be formed over the whole surface of the first core 54 and the first cladding 24 a without patterning. As a result, the manufacturing process can be reduced, and an improvement in manufacturing efficiency can be promoted.

Next, as shown in FIG. 11D, the light shielding film 52 is formed so as to the core 23 (the first core 54 and the second core 55) and the metal film 51 (the light shielding film forming process). Specifically, the light shielding film 52 is patterned so as to remain in a region corresponding to the near-field light creating portion 23 c in the side surface 23 d of the core 23.

Moreover, as shown in FIG. 11E, the second cladding 24 b is formed so as to cover the core 23 (the first core 54 and the second core 55) and the light shielding film 52 (the second cladding forming process). After that, the playback element 22 is formed on the second cladding 24 b. As a result, the recording element 21, the near-field light generating element 26, and the playback element 22 are formed on the substrate 120.

Next, the substrate 120 is diced along the Y direction in the state of being spaced for each slider 20 along the Z direction, and a bar (not shown) of the state in which a plurality of sliders 20 is aligned along one direction (the Y direction), is formed. After that, the side surface (the cutting surface) of the diced bar is polished (the polishing process). In the polishing process, the positioning of the side surface of the bar is performed by the use of an ELG (electro lapping guide). The ELG is to perform the polishing while confirming a resistance value of the ELG element and control the amount of polishing. In the present embodiment, for example, in an ELG area (a dicing table in a sliding value described later) of the bar, an ELG element and a pair of pads connected to both ends of the ELG element are formed, and the polishing is performed while causing electric current to flow to the ELG element via the pads. Then, the ELG element is also polished together with the side surfaces of the bar, and the width of the ELG element in the Z direction is reduced, whereby the electric resistance is increased. Thus, a correlation between the electric resistance of the ELG element and the amount of polishing is obtained in advance, the polishing is performed while monitoring the resistance value of the ELG element, when the resistance value reaches a predetermined value, it is decided that a desired amount of polishing is obtained, and the polishing is finished. In addition, since the ELG element or the pad has a basic function of detecting a change in electric resistance during polishing, there is no need for an extremely fine structure.

After that, the bar is cut along the Z direction so as to become sizes for each slider 20 (the slider process).

As mentioned above, the recording and playback element having the near-field light generating element 26 is completed.

In this manner, in the present embodiment, a configuration was adopted in which the width W1 of the metal film 51 is formed to be narrower than the width W3 of the side surface 23 g of the core 23 (the first core 54 and the second core 55).

According to this configuration, by making the metal film 51 smaller than the core 23, it is possible to promote a reduction in spot size of the near-field light R after suppressing a decline in propagation efficiency of laser light L propagated through the core 23. As a result, since the spot size of the near-field light R can be reduced after ensuring an amount of light, the disk D can be further locally heated.

Furthermore, by forming the first core 54 and the second core 55 by the same material, it is possible to prevent the reflection, the absorption or the like of laser light L in the interface between the first core 54 and the second core 55, and effectively propagate laser light L from one end side of the core 23 toward the other end side.

Furthermore, in the present embodiment, by forming the light shielding film 52 so as to cover the side surface 23 d of the core 23, laser light L incident to the near-field light creating portion 23 c is propagated toward the end surface 23 e while being reflected from the interface between the light shielding film 52 and the near-field light creating portion 23 c without leaking to the second cladding 24 b side. As a result, laser light L can be effectively incident to the metal film 51, which can improve the generation efficiency of the near-field light R.

In addition, in the present embodiment, in the second patterning process, a configuration was adopted in which the second core 55 is formed so as to cover the first core 54 after collectively performing the etching of the first core base material 154 and the metal film base material 151.

According to this configuration, by collectively patterning the first core base material 154 and the metal film base material 151 by the same patterning process, the width W1 of the upper bottom 51 a of the metal film 51 can be formed so as to be equal to, or coextensive with, the width W2 of the side surface 23 g of the first core 54. Moreover, by covering the first core 54 with the second core 55, it is possible to simply form the metal film 51 that is narrower than the width W3 of the side surface 23 g of the core 23 (the first core 54 and the second core 55).

Moreover, since the information recording and playback device 1 (the recording and playback head 2) of the present invention includes a near-field light generating element 26 mentioned above, it is possible to suppress an influence of the thermal fluctuation phenomenon mentioned above or the like to perform stable recording. Thus, the recording and playback of information can accurately and densely be performed, whereby the high quality can be promoted.

(Second Embodiment)

Next, a second embodiment of the present invention will be described. FIG. 12 is an enlarged cross-sectional view of a side surface of an outflow end side of a recording and playback head in a second embodiment, and FIG. 13 is an enlarged view of a portion D of FIG. 11. Furthermore, FIGS. 14A to 14C are cross-section views of the outflow end side of the recording and playback head. FIG. 14A is a cross-sectional view taken from lines E-E of FIG. 12, FIG. 14B is a cross-sectional view taken from lines F-F, and FIG. 14C is a cross-sectional view taken from lines G-G. In addition, in the description described later, the same configurations as those of the first embodiment mentioned above are denoted by the same reference numerals, and the descriptions thereof will be omitted.

As shown in FIGS. 12 to 14C, the recording and playback head 2 of the present embodiment includes the near-field light generating element 26, the recording element 21 and the playback element 22 that are sequentially placed on the side surface of the outflow end side of the slider 20 along the X direction.

In this case, the recording element 21 is molded into the second cladding 124 b, and the tip portion 33 a of the main magnetic pole 33 is placed so as to cover the side surface 23 d of the core 23. That is, the tip portion 33 a of the main magnetic pole 33 of the present embodiment also has the same role as the light shielding film 52 (see FIG. 5) mentioned above.

According to this configuration, the near-field light generating element 26, the recording element 21, and the playback element 22 are placed on the side surface of the slider 20 along the rotation direction of the disk D. In this case, the disk D is firstly heated by the near-field light R generated from the near-field light generating element 26 and then passes through the lower portion of the recording element 21 in the state in which holding force is reliably lowered. Thus, it is possible to smoothly and precisely perform the recording onto the disk D.

In addition, in the embodiment mentioned above, the core 23 of the triangular shape when viewed from the Z direction was described, but, as shown in FIG. 15, the other end side (the near-field light creating portion 23 c) of the core 23 may be formed in a trapezoidal shape when viewed in the Z direction, without being limited thereto. Even in this case, the cores 23 can be manufactured by the same method as the near-field light generating element 26 of the first embodiment mentioned above. That is, in the second patterning process, by performing the sputter-etching of the corner portion of the other end side of the Z direction in addition to the corner portions of both sides of the Y direction, it is possible to manufacture the core 23 having the other end of the trapezoidal shape. In addition, FIG. 15 is a cross-section view equivalent to FIGS. 14A to 14C.

In this manner, by forming the core 23 in the triangular shape or the trapezoidal shape when viewed from the Z direction, laser light propagated through the core 23 can effectively be reflected toward the metal film 51. In addition, the cross-sectional shape of the core 23 when viewed from the Z direction can suitably be changed in design to a polygonal shape such as a pentagonal shape without being limited to the triangular shape or the trapezoidal shape.

Furthermore, in the embodiment mentioned above, although a case was described as an example where the core 23 (the light flux focusing portion 23 b) of the light flux propagation element 25 is gradually drawn from one end side toward the other end side, as shown in FIG. 16, the core 23 may be straightly formed without being limited to this case.

(Third Embodiment)

Next, a third embodiment of the present invention will be described. FIG. 17 is an enlarged cross-sectional view of an outflow end side of a recording and playback head of a third embodiment, and FIG. 18 is a diagram taken in the direction of an arrow H of FIG. 17.

As shown in FIGS. 17 and 18, in a recording and playback head 2 of the present embodiment, the near-field light generating element 26 is placed between the coil 34 and the main magnetic pole 33 in the recording element 21. The recording element 21 in the present embodiment includes an return pole 31 and a coil 34 molded in the first cladding 24 a, a main magnetic pole 33 molded in the second cladding 24 b, and a yoke 135 that is placed between the return pole 31 and the main magnetic pole 33.

The return pole 31 is placed on the playback element 22 and is connected to one side of the yoke 135 extending along the X direction. The coil 34 is formed around the yoke 135 in a spiral shape. Furthermore, the yoke 135 is formed with a through hole 135 a penetrated through in the Z direction, and the core 23 is placed so as to be penetrated through the through hole 135 a. Furthermore, the main magnetic pole 33 is connected to the other end (the side opposite side of the return pole 31 with the core 23 interposed therebetween) of the yoke 135.

At the time of the rotation of the disk D as mentioned above, when the recording and playback head 2 is subjected to a floating force by the convex portion 20 b, the recording and playback head 2 floats to a position separated from the upper portion of the disk D by a predetermined distance D (see FIG. 2). At this time, the posture of the slider 20 during floating will be further specifically described. The slider 20 is not horizontal to the disc surface D1 but is slightly tilted. Specifically, in the state in which the outflow end side of the slider 20 becomes closest to the disk D, an angle between the disc surface D1 and the ABS 20 c of the slider 20 is tilted so as to maintain a minute angle.

Thus, according to the present embodiment, since the near-field light generating element 26 and the main magnetic pole 33 can be placed furthest to the outflow end side of the slider 20, it is possible to generate the near-field light R due to the near-field light generating element 26 and the magnetic field due to the main magnetic pole 33 in the state of becoming closest to the disk D. As a result, it is possible to smoothly and precisely perform the recording onto the disk D.

In addition, in the third embodiment mentioned above, the return pole 31, the coil 34, and the main magnetic pole 33 are placed so as to overlap with the near-field light generating element 26 when viewed from the X direction, and the cores 23 is formed so as to penetrated through the yoke 135, but the present invention is not limited thereto. For example, as shown in FIG. 19, one end sides of the return pole 31 and the main magnetic pole 33 may be bent, and the coil 34 and the yoke 135 may be offset from the near-field light generating element 26 when viewed from the X direction.

According to this configuration, since there is no need for the working such as penetrating the core 23 into the yoke 135 as in the third embodiment, an improvement in manufacturing efficiency can be promoted.

(Fourth Embodiment)

Next, a fourth embodiment of the present invention will be described. FIG. 20 is a diagram equivalent to FIG. 5 that shows a recording and playback head in a fourth embodiment. The present embodiment is different from the embodiments mentioned above in that an external end portion of a tip portion 33 a (a titled surface 211 b of a protrusion portion 211 described later) of the main magnetic pole 33 is placed on the same surface together with the side surface 23 d of the first core 54 and the sloped surface 51 b of the metal film 51. In addition, in the description mentioned below, the same configurations as the first embodiment are denoted by the same reference numerals and the descriptions thereof will be omitted.

As shown in FIG. 20, the tip portion 33 a of the main magnetic pole 33 in the recording and playback head 202 of the present embodiment has a baser portion 210 buried in the first cladding 24 a, and a protrusion portion 211 that is protruded from the base portion 210 toward the core 23 side along the X direction.

The protrusion portion 211 is formed in an isosceles trapezoidal shape that is tapered toward the core 23 side when viewed from the Z direction. Specifically, the width of the upper bottom 211 a of the protrusion portion 211 in the Y direction is formed so as to have the same width as the lower bottom 51 c of the metal film 51. In addition, the sloped surface 211 b of the protrusion portion 211 is placed on the same surface of the side surface 23 d of the first core 54 and the sloped surface 51 b of the metal surface 51. That is, the laminated body of the first core 54, the metal film 51, and the protrusion portion 211 is formed in the shape similar to the first core 54 when viewed from the Z direction. In addition, in the present embodiment, the second core 55 is formed so as to cover the first core 54 and the main magnetic pole 33 from the side surface 23 d of the first core 54 to the sloped surface 211 b of the protrusion portion 211 of the main magnetic pole 33 and the base portion 210.

The recording and playback head 202 of the present embodiment can be manufactured by going through the process that is substantially equal to the manufacturing method of the recording and playback head 2 of the first embodiment mentioned above. FIG. 21 is a process diagram for describing a manufacturing method of the recording and playback head corresponding to FIGS. 10A to 10E.

Firstly, as shown in FIG. 21A, the first cladding base material 124 a is patterned so that the opening portion 124 b is formed in the forming region of the tip portion 33 a of the main magnetic pole 33, and the base material (hereinafter, referred to as magnetic pole base material 220) of the tip portion 33 a of the main magnetic pole 33 is formed on the first cladding base material 124 a so as to bury the opening portion 124 b (the magnetic pole forming process). In addition, the opening portion 124 b of the first cladding 124 a is formed to a depth at which the insulator 35 and the proximal end portion of the main magnetic pole 33 molded into the insulator 35 are exposed. As a result, although it is not shown, the magnetic pole base material 220 is connected to the proximal end portion of the main magnetic pole 33 in the insulator 35.

Next, as shown in FIG. 21B, like the first embodiment mentioned above, after forming the metal film base material 151 and the first core base material 154, a reactive ion etching (RIE) is performed on the first core base material 154 via a mask pattern (not shown) by the same method as the first patterning process mentioned above. In this case, the first core base material 154 is patterned so that, when viewed from the Z direction, the width in the Y direction of a portion remaining in the rectangular shape in the first core base material 154 becomes narrower than the width (the width of the opening portion 124 b along the Y direction) of a portion in the magnetic pole base material 220 buried in the opening portion 124 b of the first cladding 124 a.

After that, the sputter etching is performed by the same method as the second patterning process mentioned above, and the first core base material 154, the metal film base material 151, and the magnetic pole base material 220 are collectively etched. Next, by going through the same process as that of the first embodiment mentioned above, the recording and playback head 202 shown in FIGS. 10A to 10D mentioned above can be manufactured.

In this manner, in the present embodiment, by collectively patterning the base material of the tip portion 33 a of the main magnetic pole 33 together with the first core 54 and the metal film 51 by the same patterning process, the side surface 23 d of the first core 54, the sloped surface 51 b of the metal film 51, and the sloped surface 211 b in the protrusion portion 211 of the main magnetic pole 33 are placed on the same surface when viewed from the Z direction. As a result, for example, unlike a case where the first core 54, the metal film 51, and the main magnetic pole 33 are patterned by separate processes, respectively, it is possible to precisely position the first core 54, the metal film 51, and the main magnetic pole 33. In addition, since the first core 54, the metal film 51, and the main magnetic pole 33 can precisely be positioned without using an expensive positioning device, the device cost can be reduced.

In this case, the tip portion 33 a of the main magnetic pole 33 is formed so as to cover the metal film 51 from the opposite side of the first core 54 with the metal film 51 interposed therebetween. For that reason, it is possible to position precisely the generating position of the near-field light R and the position the generating position of the magnetic field from the main magnetic field 33, which can improve the reliability of the writing of the recording and playback head 202 itself to promote increased quality.

Furthermore, even if the light flux is transmitted through the metal film 51 without causing the Plasmon resonance by the metal film 51, by reflecting the light flux to the upper bottom 211 a of the protrusion portion 211 to return into the core 23, the light flux can be incident to the metal film 51 again. As a result, the generation efficiency of the near-field light R can be further improved. In addition, since it is possible to suppress that the light flux leaks to the outside without causing Plasmon resonance by the metal film 51, it is possible to create the spot of the extremely small near-field light R only in the vicinity of the core 23.

(Fifth Embodiment)

Next, a third embodiment will be described. FIG. 22 is a diagram that shows a recording and playback head in a fifth embodiment corresponding to FIG. 5.

As shown in FIG. 22, in a recording and playback head 302 of the present embodiment, a tip portion 303 of the main magnetic pole 33 is placed between the first cladding 24 a and the metal film 51. The tip portion 303 of the main magnetic pole 33 is formed so that an end side along the Z direction is connected to a proximal end portion of the main magnetic pole 33 molded into the insulator 35, and meanwhile, the other end side is flush with the end surface 23 e of the core 23. Furthermore, the tip portion 303 is formed in an isosceles trapezoidal shape that is tapered toward the core 23 side when viewed from the Z direction. Specifically, the width of the upper bottom 303 a of the tip portion 303 in the Y direction is formed to be identical to the width of the lower bottom 51 c of the metal film 51. In addition, the sloped surface 303 b of the tip portion 303 is placed on the same surface as the side surface 23 d of the first core 54 and the sloped surface 51 b of the metal surface 51. That is, the laminated body of the first core 54, the metal film 51, and the tip portion 303 are formed in the shape similar to the first core 54 when viewed from the Z direction, and all of each side surface (and the sloped surface) of the laminated body mentioned above are covered by the second core 55, and the light shielding film 52.

FIGS. 23A to 23C are process diagrams for describing a manufacturing method of the recording and playback head corresponding to FIG. 22.

As shown in FIG. 23A, in order to manufacture a recording and playback head 302 of the present embodiment, firstly, a magnetic pole base material 304 is formed on the first cladding 24 a (a magnetic pole forming process). In addition, although not shown, the magnetic pole base material 304 is connected to the proximal end portion of the main magnetic pole 33 through the first cladding 24 a and the insulator 35.

Next, as shown in FIG. 23B, like the first embodiment mentioned above, after forming the metal film base material 151 and the first core base material 154, the reactive ion etching (RIE) is performed on the first core base material 154 via a mask pattern (not shown) by the same method as the first patterning process mentioned above. In the first patterning process of the present embodiment, by collectively etching the first core base material 154, the metal film base material 151, and the magnetic pole base material 304 along the X direction, the laminated body of the first core base material 154, the metal film base material 151, and the magnetic pole base material 304 remains in the rectangular shape.

Next, as shown in FIG. 23C, the sputter etching is performed by the same method as the second patterning process mentioned above, and the first core base material 154, the metal film base material 151, and the magnetic pole base material 304 are collectively etched. At this time, by performing the etching until the surface of the first cladding 24 a is slightly removed, all of the corner portion and the side surface of the magnetic pole base material 304 are removed, whereby the tip portion 303 having the same surface (the sloped surface 303 b) as the side surface 23 d of the first core 54 and the sloped surface 51 b of the metal film 51 is formed.

Next, by going through the same process as that of the first embodiment mentioned above, the recording and playback head 302 shown in FIG. 22 mentioned above can be manufactured.

In this manner, according to the present embodiment, the same effect as the fourth embodiment mentioned above can be exhibited, and it is possible to support the high density recording by further reducing the near-field light R generated from the metal film 51 and the magnetic field generated from the tip portion 303 of the main magnetic pole 33. In addition, in the third embodiment mentioned above, although a configuration was described in which all of the corner portion and the side surface of the magnetic pole base material 304 are removed in the second patterning process, as shown in FIG. 24, the etching may be finished in the state in which the side surface of the magnetic pole base material 304 remains, without being limited thereto.

(Sixth Embodiment)

Next, a sixth embodiment of the present invention will be described. FIG. 25 is a diagram that shows a recording and playback head in a sixth embodiment corresponding to FIG. 5.

As shown in FIG. 25, in the recording and playback head 402 of the present embodiment, a separation film 401 forming the image in the X direction between the metal film 51 and the tip portion 303 of the main magnetic pole 33. The separation film 401 is preferably constituted by an insulation material, and is formed of the same material as the core 23 (the first core 54, and the second core 55) mentioned above in the present embodiment. In addition, in a case where the first core 54 and the second core 55 are formed of materials different from each other, the separation film 401 is preferably formed of the same material as the second core 55.

According to the present embodiment, since the metal film 51 and the tip portion 303 of the main magnetic pole 33 can be electrically insulated and the alloying of the metal film 51 can be suppressed, the movement of free electrons by the metal film 51 is not adversely affected. For that reason, the generation efficiency of the near-field light R can be further improved.

In addition, the technical scope of the present invention is not limited to the respective embodiments mentioned above but include one in which various modifications are added to the embodiments mentioned above within the scope not departing from the gist of the present invention. That is, the configurations or the like described in the embodiments mentioned above are merely an example and can be suitably modified.

For example, in the embodiments mentioned above, the information recording and playback device of the air floating type was described as an example in which the recording and playback head is caused to float, but the disc and the recording and playback head may come into contact with each other if the recording and playback head is placed opposite to the disc surface, without being limited thereto. That is, the recording and playback head of the present invention may be a recording and playback head of a contact slider type. Even in this case, the same effect can be obtained.

Furthermore, the respective embodiments may be suitably combined with each other.

Additionally, the light flux propagation element 25 was described as an example in which the core 23 and the cladding 24 are integrally formed of the materials different from each other, the light flux propagation element 25 may be formed in a hollow shape. In this case, a hollow air portion becomes the core, and a portion surrounding the same becomes the cladding. Even in the light flux propagation element configured in this manner, it is possible to propagate laser light L to be incident to the near-field light generating element 26.

Furthermore, in the respective embodiments mentioned above, a case was described as an example where the recording and playback head 2 of the present invention is adopted in a vertical magnetic recording type that gives the recording magnetic field perpendicular to the disk D, an in-plane recording type may be adopted which gives the recording magnetic field parallel to the disk D without being limited thereto.

Furthermore, a method of forming the remaining portion 60 of the core 23 in the first patterning process mentioned above was described, but the core 23 other than the forming region of the core 23 may be completely removed without leaving the remaining portion 60.

In addition, the light shielding film 52 may be formed between the metal film 51 and the first cladding. That is, the light shielding film 52 may be formed over the whole periphery of the core 23. In this case, by reflecting laser light transmitted through the metal film 51 and returning into the core 23 without causing the Plasmon resonance by the metal film 51, laser light can be incident to the metal film 51 again. As a result, the generation efficiency of the near-field light R can be further improved.

Furthermore, in the embodiments mentioned above, the core 23 was constituted by two layers of the first core 54 and the second core 55, the core 23 may be constituted by three layers or more without being limited thereto.

In addition, in the embodiments mentioned above, a case was described where the width W1 of the metal film 51 is formed to be equal to the width W2 of the first core 54, but the width W1 may be narrower than the width of the second core 55 without being limited thereto. That is, the metal film 51 may be formed to be narrower than the first core 54.

Furthermore, a configuration may be adopted in which laser 43 is mounted on a back surface (a surface of an opposite side of the opposite surface 20 a) of the slider 20 and laser light L is directly introduced into the light flux propagation element 25 without passing through the optical waveguide 42. 

What is claimed is:
 1. A near-field light generating element, comprising: a core that propagates light flux introduced to one end side thereof while focusing the light flux toward the other end side thereof; and a near-field light generating portion disposed long a propagation direction of the light flux at the other end side of the core to generate near-field light from the light flux, wherein the core includes a first core that is disposed on the surface of the near-field light generating portion and that has a bottom face coextensive with the width of the near field light generating portion when viewed from the propagation direction, and a second core that covers the first core from an opposite side of the near-field light generating portion with the first core interposed therebetween, and wherein an external end portion of the second core is situated further to the outside than an external end portion of the near-field light generating portion when viewed from the propagation direction.
 2. The near-field light generating element according to claim 1, wherein the first core and the second core are formed of the same material.
 3. The near-field light generating element according to claim 1, further comprising: a cladding that covers the core in the state of exposing the other end surface of the core to the outside, wherein the first core, the second core, and the cladding are configured so that refractive index is increased in the order of the cladding, the second core, and the first core.
 4. The near-field light generating element according to claim 1, wherein the other end surface of the core is formed in a triangular shape or a trapezoidal shape when viewed from the propagation direction.
 5. The near-field light generating element according to claim 1, wherein a light shielding film is formed so as to cover the second core from the opposite side of the first core with the second core interposed therebetween.
 6. The near-field light generating element according to claim 1, wherein the first core has a plurality of side surfaces extended along the propagation direction, the plurality of side surfaces includes a first side surface on which the near-field light generating portion is disposed, and a second side surface disposed along a direction intersecting a plane direction of the first side surface on both sides of the first side surface when viewed from the propagation direction, and the external end portion of the near-field light generating portion is disposed on the same surface as the second side surface of the first core when viewed from the propagation direction.
 7. A near-field light head which heats a magnetic recording medium rotating in a given direction and causes a magnetization reversal by applying the recording magnetic field to the magnetic recording medium to record information, comprising: a slider disposed opposite a surface of the magnetic recording medium; a recording element that is disposed on a tip side of the slider and has a magnetic pole for generating the recording magnetic field; the near-field light generating element according to claim 1, that is fixed adjacent to the recording element in the state where the other end side faces the magnetic recording medium side; and light flux introduction means fixed to the slider for introducing the light flux from the one end side into the core.
 8. The near-field light head according to claim 7, wherein the first core has a plurality of side surfaces extended along the propagation direction, the plurality of side surfaces includes a first side surface on which the near-field light generating portion is disposed, and a second side surface disposed along a direction intersecting a plane direction of the first side surface on both sides of the first side surface when viewed from the propagation direction, and the magnetic pole is disposed opposite to the first side surface of the first core with the near-field light generating portion therebetween, and an external end portion of the magnetic pole is disposed on the same surface as the second side surface of the first core when viewed from the propagation direction.
 9. The near-field light head according to claim 7, wherein, between the near-field light generating portion and the magnetic pole, a separation film is formed which forms an image between the near-field light generating portion and the magnetic field.
 10. An information recording and playback device comprising: the near-field light head according to claim 7; a beam that is movable in a direction parallel to the surface of the magnetic recording medium, and supports the near-field light head on a tip side in the state of being rotatable around two axes which are parallel to the surface of the magnetic recording medium and are perpendicular to each other; a light source that makes the light flux incident to the light flux introduction means; an actuator that supports a proximal end side of the beam and moves the beam toward a direction parallel to the surface of the magnetic recording medium; a rotation driving portion that rotates the magnetic recording medium in the given direction; and a control portion that controls the operation of the recording element and the light source.
 11. A near-field light generating element, comprising: a core portion having a light incident side and a light emission side and being configured to propagate light flux introduced to the light incident side to the light emission side while focusing the propagating light flux, the core portion comprising a first core that extends from the light incident side to the light emission side and that tapers inwardly at the light emission side, and a second core that covers only a part of the surface of the first core at the light emission side of the first core; and a near-field light generating portion that is disposed along a propagation direction of the light flux in contact with a surface of the first core, at a location where the surface of the first core is not covered by the second core and that generates near-field light from the light flux.
 12. A near-field light generating element according to claim 11; wherein the light emission side of the first core terminates in an end face having a width when viewed from the propagation direction that is coextensive with the width of the near-field light generating portion when viewed from the propagation direction.
 13. A near-field light generating element according to claim 11; wherein, when viewed from an end face of the light emission side, the part of the first core which is not covered by the second core is coextensive with the near-field light generating portion.
 14. A near-field light generating element according to claim 11; wherein the light emission side of the first core terminates in an end face having a triangular shape or a trapezoidal shape when viewed from the propagation direction.
 15. A near-field light generating element according to claim 11; wherein the light emission side of the core portion terminates in an end face; and further comprising a cladding that covers the core portion but not the end face, wherein the first core, the second core, and the cladding are configured so that refractive index is increased in the order of the cladding, the second core, and the first core.
 16. A near-field light generating element according to claim 11; further comprising a light shielding film that covers the second core from the opposite side of the first core with the second core interposed therebetween.
 17. A near-field light generating element according to claim 11; wherein the first core has a plurality of side surfaces extended along the propagation direction, the plurality of side surfaces including a first side surface on which the near-field light generating portion is disposed, and a second side surface disposed along a direction intersecting a plane direction of the first side surface on both sides of the first side surface when viewed form the propagation direction.
 18. A near-field light generating element according to claim 11; wherein the near-field light generating portion comprises a metal film formed on the surface of the first core.
 19. A method of manufacturing a near-field light head which includes a near-field light generating element and which heats a magnetic recording medium rotating in a given direction and causes a magnetization reversal by applying a recording magnetic field to the magnetic recording medium to record information, the near-field light generating element including: a core that propagates light flux introduced to one end side while focusing the light flux toward the other end side, and a near-field light generating portion which is placed along a propagation direction of the light flux facing from the one end side toward the other end side in the core to propagate the light flux along an interface between the near-field light generating element and the core, and generates the near-field light from the light flux, the method comprising: a near-field light generating portion forming process of forming a base material of the near-field light generating portion; a first core forming process of forming a base material of the first core of the core so as to cover the near-field light generating portion; a patterning process of collectively patterning the base material of the first core and the base material of the near-field light generating portion; a second core forming process of forming a second core of the core so as to cover the first core from the opposite side of the near-field light generating portion with the first core interposed therebetween; a magnetic pole forming process of forming a base material of a magnetic pole that generates the recording magnetic field before the near-field light generating portion forming process, and wherein, in the patterning process, the base material of the magnetic pole is collectively patterned by the same process together with the base material of the first core and the base material of the near-field light generating portion. 